Electronic paper is a new display technique. One outstanding advantage of the electronic paper lies in the maintenance of the image. The electronic paper can maintain the image that it displays for a long period of time without power supply. Only when change in the image that it displays is needed is change implemented by applying electric field through electrodes. This saves plenty of energy.
Electrophoretic ink is crucial to the performance of the electronic paper. Electrophoretic ink comprises electrophoretic ink microcapsules, microcups and Gyricons. Here, electrophoretic ink microcapsules are taken as an example. Many small-volume “microcapsules” adhere to the surface of an electrophoretic ink screen, in which negatively charged black particles and positively charged white particles are encapsulated. By changing the charges to allow particles of different colors to arrange orderly, a visual effect of starkly contrasted black and white can be exhibited, as shown in FIG. 1. FIG. 1 is a schematic diagram of an electronic paper. The left panel is the magnified view of the electrophoretic ink microcapsules. This electronic paper comprises a top display electrode 1, a bottom electrode 2 and an electrophoretic ink microcapsule layer disposed therebetween.
However, many aspects of the current electrophoretic ink needs to be improved, for example, dynamic state images are displayed slowly, static state images are poorly maintained, and so on.
In the prior art, an electrophoretic ink display is implemented by utilizing the “bistable state” of an electrophoretic solution, that is, the density of the small display particles (spheres) is equivalent to the density of the electrophoretic solution, and thus after a power supply is switched off, the image remains unchanged.
However, there still exist the following issues in the current electrophoretic solution.
1. The electrophoretic solution, due to its equivalent density to the small display particles (spheres), can only ensure that the small display particles (spheres) do not go up and down, but cannot ensure that the image is “locked” from the external influences, for example, shaking of the display screen under external forces, external strong fields, etc.
2. The resistance of the electrophoretic solution to the small display particles (spheres) is constant no matter whether an image is to be changed by applying an electric field to the electrodes or an image is to be maintained in the static state. However, when the image is to be changed, the resistance of the electrophoretic solution to the small display particles (spheres) is unnecessary, whereas in image maintenance in the static state, such resistance is necessary.